Mobile IPv4 (Internet Protocol version 4) is in general a protocol enhancement that is designed to allow mobile device users to move from one network to another while maintaining their permanent IP address. That is, mobile IP allows transparent routing of IP datagrams to mobile nodes (MN) in the Internet. Each mobile node is always identified by its home address, regardless of its current point of attachment to the Internet. When situated away from its home, a mobile node is also associated with a care-of address, which provides information about its current point of attachment to the Internet.
There are two kinds of network entities in Mobile IP:                A home agent (HA) stores information about mobile nodes whose permanent address is in the home agent's network.        A foreign agent (FA) stores information about mobile nodes visiting its network. Foreign agents also advertise care-of addresses, which are used by Mobile IP.        
Data packets are sent to a mobile node using the home address of the mobile node. If the mobile node is situated in a foreign network, these packets are intercepted by the home agent, which tunnels the packets to the mobile node's care-of address with a new IP header, preserving the original IP header. The foreign agent in the foreign network then decapsulates the packets at the end of the tunnel to remove the added IP header and delivers the original packets to the mobile node.
In other words all user traffic has to flow through foreign agent and home agent. In broadband communication networks the amount of such traffic can be significant and may exceed 1 Gbps. However, the most popular physical connection between a foreign agent and a home agent (with potentially multiple hops) is Gigabit Ethernet (GE). That is, the amount of user traffic may exceed capacity of the single link physical connection between a foreign agent and a home agent.
This causes the problem of how to fit the user traffic, which may well constitute multigigabit traffic, into the physical connection between a home agent and a foreign agent.
In order to increase capacity there may be multiple parallel GE links between a home agent and a foreign agent. In general, there are few schemes (all similar) for dividing or balancing load between multiple physical links. One example of such scheme is Equal Cost MultiPath (ECMP) on IP level, another one is Ethernet Link Aggregation (802.3ad) with corresponding Link Aggregation Control Protocol (LACP). The requirement for any such load balancing scheme is preservation of packet order for the same user flow, meaning that all packets for the same user “conversation” (defined usually by 5-tuple—Layer 3 IP source and destination, address, Layer 4 protocol and Layer 4 source and destination ports—or sometimes even more) have to go through the same physical link. Such schemes work well in non-tunneled traffic, because the load balancing can be based either on Layer 2 (MAC address), or Layer 3 (source/destination IP), or even Layer 4 (UDP/TCP ports).
However, in mobile IP all user packets are encapsulated between FA and HA into a tunnel (for example an IP-in-IP tunnel). It means that from point of view of the network devices between FA and HA the entire user traffic (for all mobile subscribers) is a single IP flow or conversation between FA IP address and HA IP address. Thus none of the load balancing schemes can be used, because all layers (L2, L3, and L4) are always the same for all packets inside the tunnel. This results in that the network may be forced to fit the multigigabit mobile IP traffic into single GE link, which clearly causes throughput problems.
It is noted that higher speed links than 1 gigabit links may be available (for example 10 gigabit link may be possible), but such links are expensive and may require optical infrastructure, which is not always available.
Hence, there is a need for a new approach which would avoid and/or mitigate the problems associated with the present solutions.